Promoting a reliable electricity supply: Frequency-related Code amendment proposals

The Electricity Authority Te Mana Hiko is seeking feedback on a proposal to amend Part 8 of the Electricity Industry Participation Code 2010 (Code) to address increased frequency variability in New Zealand’s power system. This is caused by the growing amount of variable and intermittent resources, including wind and solar generation.

This consultation is part of our work programme to ensure our power system remains secure and resilient as the country moves towards a lower emissions economy with more renewable generation.

The proposed changes address the first of seven issues identified by our review of common quality requirements in Part 8 of the Code. These requirements are foundational to the safe and reliable supply of electricity to consumers.

The variability and intermittency of technologies like wind and solar generation is likely to cause more variability in frequency within the ‘normal band’ of 49.8-50.2Hz. This variability is likely to be compounded over time by decreasing system inertia. To address this issue, we are proposing the following:

• lower the 30MW threshold for generating stations to be automatically excluded from being required to comply with aspects of Part 8 of the Code. These are the frequency-related asset owner performance obligations and technical codes
• set a permitted maximum dead band beyond which a generating station must contribute to frequency management and frequency support.

These proposed changes will benefit consumers by:

• promoting a reliable electricity supply by improving frequency stability and reducing the risk of an automatic under-frequency load shedding event
• promoting efficiency by reducing the need for the system operator to procure additional ancillary services, lowering the possibility of future cost increases.

Our proposal follows on from our consultation Addressing more frequency variability in New Zealand’s power system, which set out short-listed options to address this issue.

We welcome your feedback on our proposal by 5pm, Tuesday 17 June 2025 and will share our decisions in late 2025.

View consultation